This paper analyses the presence ofmundus inversus literary topos in the Book ofTobit. Noting that it is used at all levels that specialized literature remarks, we find that the author uses it to reinforce his message to readers: God can transform the most difficult situations. Dangers and threats that affect the characters in the novel will be straightened up once we accept that they can go beyond the usual boundaries and that God can turn negative realities into blessings... others that better what can be expectedfrom human beings.